Doorcheck



L. N. HOFFMAN July 5 1933a DOORCHECK Filed Feb. 4. 1932 M m T M z m Q Ua L i A ZTORN Patented July 4, 1933 UNITED STATES PATENT OFFICE LAURENCEN. HOFFMAN, OF SHELBY, OHIO, ASSIGNOR TO THE SHELBY METAL PRODUCTSCOMPANY, OF SHELBY, OHIO, A CORPORATION OF OHIO DOOR-CHECK Applicationfiled February 4, 1932. Serial No. 590,884.

The present invention relating as indicated to a door check, has moreparticular reference to a pneumatic cylinder type of door closing devicedesigned primarily for application to doors of lighter construction,such as screen doors. It is particularly desirable in screen doorinstallations to provide a form of door check which may be convenientlyattached and removed due to the fact that the door it- "1 self is not apermanent fixture, but is reu to provide means for regulating the rateof flow of the compressed air from the interior of the'pneuinaticcylinder and to provide means for producing var'able velocity of thedoor closing motion. Further advantages shall become apparent as thedescription proceeds. To the accomplishment of the foregoing and relatedends, said invention, then, consists of the means hereinafter fullydescribed and particularly pointed out in the claims. r

The annexed drawing and the following description set forth in detailcertain mechanism embodying the invention, such disclosed meansconstituting, however, but one of vaious mechanical forms in which theprinciple of the invention may be used.

In said annexed drawing:

Fig. 1 is an elevational assembly view of the pneumatic door checkembodying the principle of my invention; Fig. 2 is a plan view of Fig.1, showing the door check device in position upon the door and doorcasing and with the cylinder and piston in section; Fig. 3 is a sectiontaken substantially upon the line 33 of F ig. 1; Fig. 4c is a sectiontaken substantially upon the line i4 of Fig. 1; Fig. 5 is an enlargedfragmentary sectional view of the compression end of the pneumaticcylinder; Fig. 6 is a sectional view of the door closing tension spring;Fig. 7 is a matic cylinder 1 having the piston rod 2 and piston 3positioned therein for reciprocal operation. The piston 3 may be of anysuitable construction satisfactory for pneumatic operation. The cylinder1 is carried upon its open or non-compression end by thc threaded cap 4,which has a laterally proiecting stud 5 pivotally mounted with in thesleeve 6 of the door bracket 7. -The bracket 7 may be permanentlysecured to the door by means of wood screws, bolts, clamps, or similarfa tening means.

As best illustrated in Fig. 1, the door casing bracket 9 has a pair of prallel horizontally projecting plates 10 and 11 which are adapted toremovably receive the transversely bent portion 12 of the piston rod 2.The coilcdtension spring 13 having the tangentially extending endportions let and 15 is adapted to be carried between the bracket plates10 and 11 and to engage the piston rod 2. The bracket 9 may bepermanently secured to the door casing 16 by suitable wood screws 17 Itwill be seen, however, that although the bracket 9 itself is a.permanent installation, that the projection 12 of the piston rod 2 andthe tension spring 13 are in removable engagement with the bracket.Likewise directing attention. more particularly to Fig. 3, it will beseen that the pneumatic cylinder 1 is in removable engagement with thedoor bracket 7.

Referring to Fig. 4,. the tension in the door casing spring 13 may bevariably. adjusted by means of. positioning the vertical projection 18of the tangential spring extension 15 in any one of theholes 19 to 22inclusive drilled in the bracket plate 11.

In order to variably control the rate of flow of the air from theinterior of the pneumatic cylinder and, consequently, to vary thepneumatic pressure resistance, there is provided in the compression end25, the tapered screw 26 threadedly engaging therewith. It will thus beseen that varying positions of threaded engagement of the tapered screw26 in the end wall 25 will correspondingly produce a larger or smallerescape opening for the compressed air. A compression spring 27 ispositioned between the head of the tapered screw 26 and the exterior ofthe piston wall 25 in order to maintain the screw in adjusted position.

In order to impart a closing movement to the door, which ischaracterized by relative rapid motion toward closed position during thefirst part of the closing arc, and then substantial retardation for thelast foot or so, followed by final rapid closing movement; there areprovided a pair of by-passes 31 and 32. The by-pass 32 consists of anenlarged portion of the cylinder wall of the pneumatic cylinder 1 and isadapted to temporarily relieve the pneumatic pressure while the pistonis moving in that particular portion of the cylinder. When the doorarrives substantially at half closed position, the piston 3 willcorrespondingly arrive at the portion 33 of the cylinder at which pointthe pneumatic pressure will again become substantially increased so thatthe door closing motion will undergo deceleration.

The purpose of the smaller lay-pass 31 positioned in the compression endof the pneumatic cylinder 1 is in order to impart a final rapid closingaction to the door movement. Such a rapid final action is particularlydesirable where snap latches are installed on the door.

A coiled spring 30 is positioned in the nonrompression end of thecylinder 1 and is adapted to engage with the piston 3 and the cylindercap 4 in order to absorb any shocks caused by too forcible opening ofthe door, and likewise to aid in an initial closing ac tion.

In the light of the foregoing description it will thus be seen that Ihave provided a unique form of construction of door closing means whichis applicable and adjustable to various conditions of installation. Theadjustable features found to reside in the closing spring 13 and in theadjustable screw 26 are of particular advantage when the device is to beapplied to doors of varying weight and size.

By means of the expedient of pivotally supporting the pneumatic cylinderat its noncompression end, it will become apparent that the cylinderitself will always be located in a position parallel to the door whenthe door is closed, so that, as well as offering an attractiveappearance, no unnecessary space will be occupied.

Other modes of applying the principle of my invention may be employedinstead of the one explained, change being made as regards the mechanismherein disclosed, provided the means stated by any of the followingclaims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention:

1. In a door check, the combination of a pneumatic cylinder, a pistonoperably positioned within said cylinder, a central portion in the wallof said cylinder raised out of contact with said piston and adapted toserve as a fluid by-pass, and a portion adjacent the compression end ofthe wall of said cylinder raised out of contact with said piston.

2. In a door check, the combination of a pneumatic cylinder, a pistonoperably positioned within said cylinder, a central portion in the wallof said cylinder raised out of contact with said piston and adapted toserve as a fluid by-pass, a portion adjacent the compression end of thewall of said cylinder raised out of contact with said piston, means forregulating the rate of flow of air from the interior of said cylinderconsisting of a tapered screwthreada-bly positioned in the compressionend of said cylinder, and bracket means removably attached to the0pposite end of said cylinder for pivotally securing said cylinder tothe door.

3. In a door check, the combination of a pneumatic cylinder, a pistonoperably positioned within said cylinder, a piston rod, a centralportion of the wall of said cylinder raised out of contact with saidpiston and adapted to serve as a fluid by-pass, a portion adjacent thecompression end of said cylinder raised out of contact with said piston,a bracket secured to the door casing adapted to removably engage saidrod, a tension spring associated with said bracket and rod, and aplurality of holes in said bracket to receive one end of said spring andto forcibly adjust the tensional resistance thereof, means forregulating the rate of flow of air from the in terior of said cylinder,and bracket means removably attached to the non-compression end of saidcylinder for pivotally securing said cylinder to the door.

LAURENCE N. HOFFMAN.

Signed by me this 3rd day of February,

